[Reeman]

Could be stem seals if you park after a long drive with the engine hot. Of course it all depends upon mileage. If you are up around 180 thousand or more it is possible and a frequent problem with more than just GM engines.

The stem seals heat up and seal, if you sit after a long hot run then they shrink and let a little oil through until they warm up again. It does not sound like you have the same problem as mentioned earlier in this thread otherwise the smoke would be much worse and last much longer.

I have had several 4 cylinders and one v8 that developed intermittent stem seal leaks at 150-200 thousand miles. In all cases I changed the seals and in the case of the v8 changed a weak spring and a couple of warn rockers.

This is not major engine repair but can lead to more serious issues if left unattended causing at a minimum bad carbon build up and cat converter plug up or as my brother calls it catyleptic corn boiler congestion. ;-)

 

[jwblady]

I am having this same issue. I work an hour from home, and after the drive i let it sit, and then after a couple of hours at around 10am i go out crank it and it smokes then disappears. This is the only time it smokes on the same drive home let it sit for a couple of hours and it doesn't smoke so i am leaning towards moisture getting into the exhaust somehow since this is the only time it does it, and yes i have to take interstate to work. This didn't start until February after changing oil and spark plugs which i guess is a coincidence , but its funny cuz up until that point i never had to put any oil in my truck besides oil changes, now i know in the past month i have bought 4 quarts of oil, and the fuel consumption differs daily on the same exact drive which has me at a stand still, so if there is anything anyone can help me with suggestions would be greatly appreciated.. the smoke is embarrassing, at least if i crank it at 10 it doesn't smoke at 3 when i leave from work. Oh and is there drain holes in the muffler that could be stopped up that could cause this moister if that is what it is.???? please help...

 

[Colorado1184]

Hey guys, I'm new here so late it easy lol. I've been experiencing the same problem as the op. I drive about 55miles on the highway round 70-75mph, the trucj sits for about 8-9hours while im at work, i leave work and it appears as if someone has thrown a smoke grenade under my truck, but i again drive the excat same way home, let the truck sit over night, and very little smoke in the morning, i cant seem to figure this out, ive been told many different possibilities as to what cpuld cause this, ive recently developed a misfire in random cylinders, when i did my spark plugs last i noticed there were soaked in oil, but i only really starting noticing the smoke after i did an oil change... Hope i didnt confuse anyone, and ideas or advice would be greatly appreciated.

 

[DaleHutch]

I just developed this problem. Is pulling the valve cover and cleaning the tabs the fixed? Thanks

 

[Hummer3.5i5]

I have the same engine and I'm almost positive that this is my problem. (The baffle and tabs problem) I have a question and maybe a solution could I add an oil catch can kit between the valve cover and the where it hooks back into the resonator box?

 

[fluf]

I have a "2005" Canyon with an I-5, it suddenly developed a problem with smoking heavily at start up. I tried to deduct what the problem could be, it happen suddenly so it's not valve stem seals. I found another Canyon owner who said he had the same problem previously, he told me that the pcv valve is plugged and when I start my truck the intake sucks the oil that didn't drain off the pcv system plates, once it sucks all the remaining oil off, it quits smoking. It turns out that some genius at Gm decided to put the pvc system underneath the engine cover, the top of the motor. And the plate in the pvc system has a small hole in it that lets the oil drain off of it, well after awhile this hole becomes plugged and causes it to occasionally smoke heavily on start up. I had to take the alot of stuff off the motor to get to two bolts covered by the intake manifold. I have a GM repair manual that was offered in the owners manuals it told me how to get the cover off, I had to loosen the AC pump also, it was a big job for a DIY guy like me, but I got to that plate and unplugged the hole, and drilled two more the same size near the original hole. Put it all back together and hoped for the best, and I'll be, it worked and has never smoked again. If you do this, get prepared, you will need some new gaskets, and some time. I took mine apart on a Friday after work, and put it back together on Saturday. Take your time and take many pictures of the way things were before you took it apart, it will help. Good luck.

 

[bnsfdjr]

fluf, any update on this and do you have pics you can share? I don't see issues on start up, but do notice oil usage after about 500 miles.

 

[fluf]

Well,it's been quite awhile and still no smoke on start up, and no I don't have any pictures anymore. But remember that my truck did not smoke, or use excessive oil before this happened. Suddenly I started it up one day in the garage and my garage filled with smoke, but did not do it every time I started it up. I drive very few miles a day, and it seemed to smoke at start up every couple days. Taking the top of my 3.5 motor apart to unplug the PCV holes did the trick, I also added two more holes of the same size in the plate, close to the original holes. It was a big job for me to tackle, but was able to do it in a day, and am very glad I did it. No more smoke on start up ever, and no oil leaks. I used a GM repair manual, that I purchased from the back of my owners manual, to tell me how to take the engine apart, to get to the PCV valve. If the issue ever comes up again,I will gladly unplug the hole again.